Smaller, less visible antennas are an increasing trend in vehicle design. One approach for providing these antennas employs a crossed-slot antenna. The crossed-slot antenna can receive signals from satellite radio broadcasting systems such as satellite digital audio radio system (SDARS). Crossed-slot antennas can be as thin as a small fraction of one wavelength tall when combined with a resonant cavity. The reception characteristics and the relatively small size of crossed-slot antennas are ideal for mobile receiver applications.
Conventional fabrication techniques for crossed-slot antennas require the use of low-loss dielectric materials such as Teflon or Duroid. These materials may be prohibitively expensive for commercial applications such as high-volume automobile manufacturing. Absent these specialized low-loss materials, the internal dielectric loss of the crossed-slot antenna is unacceptably high.
Conventional fabrication methods for the crossed-slot antenna employ printed circuit boards. A circuit board is initially plated with a suitable metal, such as copper, which acts as the antenna. Typically, slots are made in the antenna using standard photolithography techniques. The printed circuit board is formed with a suitable dielectric material and acts as a cavity for the antenna.